The drogue
handled well throughout the test. No problems were encountered in
deploying or retrieving the equipment and no deterioration or damage was
noted after the tests. In the speed range where the drogue would normally
operate (under 15 f t/sec) , the average measured drag coefficient was 0.6
based on a drag area equivalent to ninety 5inch diameter cones for a total
of 12.3 square feet. For the acceleration runs, which are similar to a
breaking wave strike, the drag coefficient was 0.6 or greater when the
drogue first took up the load. As the speed continued to increase, the
drag coefficient dropped to 0.5 or less as the drogue straightened and the
first few elements began to pull out of the water. Based on this testing,
it is considered reasonable to use a drag coefficient of 0.6 for
estimating the drag of a series
drogue.
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